Comparative effects of adipose-derived mesenchymal stem cells and their exosomes on interleukin-1 beta-induced testicular inflammation in rats: An experimental study

Abstract Background Elevated interleukin-1 beta (IL-1β) in orchitis triggers immune-mediated inflammation, disrupting spermatogenesis and impairing reproductive function. Objective This study compared adipose-derived stem cells (ASCs) and their exosomes (EXO) for mitigating inflammation and enhancing repair in IL-1β-induced orchitis. Materials and Methods In this experimental study, ASCs were isolated and cultured to passage 3. Flow cytometry and immunocytochemistry confirmed ASCs' surface markers; scanning electron microscopy characterized EXO. 32 male Wistar rats (6–7 wk; 250–300 gr) received daily intraperitoneal IL-1β (10 μg/kg) for 6 days to induce testicular inflammation. Rats were assigned to 4 groups: 1) control; 2) IL-1β only; 3) IL-1β + ASCs (1 × 10⁶ cells); and 4) IL-1β + EXO (200 μg). After the treatments, testicular histopathology, hematoxylin and eosin staining, and leukocyte infiltration were evaluated. Results ASCs displayed spindle morphology and positivity for CD44 and CD105. Isolated EXO averaged 82.6 ± 28.5 nm in diameter. IL-1β induction caused considerable leukocyte infiltration, Sertoli cells displacement, vascular congestion, and disrupted seminiferous tubule structure. ASC administration yielded partial tissue recovery and reduced degenerative alterations. EXO demonstrated superior efficacy, significantly reducing leukocyte infiltration (p = 0.011) and restoring near-normal testicular structure. Exosome treatment also outperformed ASCs in alleviating epididymitis. Conclusion Both ASCs and exosome therapies reduced IL-1β-induced inflammation in the rat testis and epididymis. EXO demonstrated superior efficacy, highlighting their significant potential for treating inflammation-induced testicular injury.